The Department of Foreign Affairs has confirmed that two Irish diplomats who were providing consular assistance to the family were refused access to the Salam Security camp this afternoon.

It is understood that diplomats attached to two other states were also refused access.

Khadija Halawa, a sister of the four, said that at a hearing this afternoon, their lawyers requested that they be freed as soon as possible.

She said the lawyers told them that they would find out on Saturday or Sunday if they would be freed.

They also requested that Irish representatives be allowed attend the next hearing.

Elsewhere, Egyptian police captured senior Muslim Brotherhood official Mohamed El-Beltagi as they pressed on with a crackdown that has put most of the Islamist group's top leaders behind bars.

Mr Beltagi, secretary-general of the Brotherhood's Freedom and Justice Party, had urged Egyptians to join rallies against the military tomorrow, in a recorded statement aired by Al Jazeera television news network this week.

Since deposing president Mohammed Mursi and his Muslim Brotherhood government on 3 July, the military-backed authorities have killed hundreds of pro-Mursi protesters and arrested the bulk of the Brotherhood's leaders in what they call a fight against terrorism.

The Brotherhood's top leader, Mohamed Badie, and his deputies Khairat al-Shater and Rashad Bayoumy have already been put on trial on charges including incitement to violence in connection with a protest on 8 July, in a prosecution they dismiss as politically-motivated.

Mr Beltagi was a prominent speaker at a pro-Mursi protest camp at the Rabaa Adawiya mosque that was smashed by the security forces on 14 August, on a day when more than 600 people died.